Door latch operating mechanism



June 4, K94. M FALK 2AL559 DOOR LATCH OPERATING MECHANISM Filed Nqv. l, 1945 INVENTOR Morris iZ/i ATTORNEY Patented June 4, 1946 j UNITED STATES PATENT OFFICE DOOR LATCH OPERATING MECHANISM Morris Falk, Leominster, Massdassignor to Independent Lock Company, Fitchburg, Mass., a corporation of Massachusetts Application November 1, 1943, Serial No. 508,454

Claims. a 1

This invention relates to door latches, and more particularly to latches operable by a thumb depressible lever.

Known to me is the provision of latches for doors in which operation of the latch bolt is efiected on one side of the door by a thumboperated lever which is grasped by the fingers of the-hand in holding the door handle, so that the same motion of grasping the handle conveniently locatesa pivotal thumb operated lever whereby the depression of .this lever actuates the latch bolt to withdraw. it from engagement with the door strike. In such a mechanism room must be made in the door frame to mount and'support linkage leverswhich occupy substantial space, all of whichrequire considerable morticing operations in order tofitthis mechanism into positionon the door frame. t

Recently I have developed a door latch which fits within a substantially tubular casing and which may be fitted on the door edge by simple boring operations. .This form of latch, claimed in my Patent No. 2,293,645 granted August 18, 1942, is actuated by a spindle wherein a relatively small arcuate turning of the operating spindle serves to move the latch bolt for a multiple distance of the linkage actuated by the retractor to which the spindle is connected. This form of latch has heretofore been operated by door knobs extending to either face of the door and connected to the latch bolt operating spindle.

In accordance with my invention'it is contemplated by me to provide a latch bolt operating mechanism wherein movement of the latch bolt is efiectedby a thumb operable lever which transmits the movement of the lever to the'rotatable spindle to retract the latch bolt.

l It is a further object of my invention to provide a door latch in which the latch bolt is retracted by a thumb operated lever to transmit .the pivotal movement of the thumb operated lever to the rotatable spindle for actuating the latch bolt and 'to provide mounting means for the same substantially in thesame plane 'as the spindle which operates the latch bolt.

A still further object of my invention resides in the'provision of a latch bolt in which the latch bolt is r'nanipulatedon one side of the door by a thumb operable pivotal lever and which carries forward simplicity of construction and compact- 'ness of parts, requiring the minimum of fitting operations such as in morticing the door, while i still providing efiicient actuation and a compact and neat assembly.

I To attain these objects as may appear herein Figure 4 is an exploded perspective view of the essential elements entering into ating mechanism; I

Figure 5 is a longitudinal view of the latch bolt casing with one cover removed to expose the latch operthe operatingparts. V

Making preference to the drawing, there is shown a fragmentary portion of a door In viewed edgewise in which is mounted a latch casing ll held in position by'a plate I 2 employing screws l3 which engage the door edge. From an orifice: in the plate a latchbolt." projects as part of the shank l5 and which is arranged to be retracted by the hub I6 carrying the retractor l1 actuating the link It for slidable movement. The link 18 is formed with a camming portion I9 engaging the pivoted lever which has on one end a leaf spring 2| and on the other end a finger 22 adapted to engage the shank 15. A spring 20 normally projects the latchbolt l4 outwardly. Rotation of thehu'b l6 draws with it the link IE to pivot the finger 22 and withdraw .the latch bolt for a multiple distance of movement of the link I8. This construction ismore particularly described and claimed in my prior patent aforementioned.

The hub I6 is provided with a keying orifice 23 through which, a spindle 24 passes and is operated by the inner door knob 25 toone side of mechanism includea door handle 23, the lower edge of which terminates on the plate 29, being held by the nut 3!] andafiixed against displacement by the headed bolt 3!. The handle 28 has its" upper end portion passing through the orifice 32 and boltecLat 33 to the plate 34 in which the orifice 32 is formed. The plate 34 serves as an escutcheon covering the morticed opening 2'! previously described.

The spindle fl has a ,free end which eirtends "into the morticed opening. 21, formed with a,

squared keying shoulder 35 arranged to fit into the correspondingly shaped opening 36 of the laterally projecting finger plate 31. The extreme free end of the spindle 24 is formed with a cylindrical section 38 arranged to rotatably move with in the boss 39 extending from the rear surface of the plate 34 and within the bearing orifice 40 formed therein. Assembly is effected by mounting the finger plate 31 to fit upon the shoulder portion 35; thereupon the cylindrical section 38 is directed into the bearing 40 of the stud 39. In this position the cross pin 42 is projected through the arcuate slot 4| to engage the transverse orifice 43 formed through the cylindrical portion 38 of the spindle 24. The pin 42 is permitted to project into the slot 4|. The slot 4| has stops 45 and 45 to limit the rotational move.-

ment of the spindle 24 in a manner which will be readily understood.

The front face of the plate 34 is formed with ears 4'! and 48 for mounting the thumb operable lever 49, which is formed with a finger 50 passing through the opening. 50:; formed in close adjacency to the stud 39. The cross pin passing through the hole 52 and the ears 41 and 48,- serves to mount the thumb operable lever 49 upon the plate 34. An extension tongue 53 formed on the lever 43 is arranged to abut the front face of the plate 34, thereby to limit the pivotal movement of the thumb operable lever upon the plate in a mannerreadlly understood. The finger 50 in end thereof, a latch lever pivotally mounted on projecting through, the orifice 50a engages the,;,;

laterally projecting extension finger 31 carried by the spindle 24 in its bearing 40.

Normally the springs 20 and.2 I. serve to project the latch bolt l4 and. act upon the camming member l9 to draw the sli-dable link [8 forwardly.

These act against the retractor 11 to hold the hub 16 in the normal position resiliently. Thus the hub, by reason of the resilient pressure exerted against the retractor .II, tends to return to its normal position shown in Figure 5.

Depression of the thumb operable lever 49 when the hand grasps the handle 28 tilts the finger 50 upwardly, engaging the laterally extending finger 31 to rotate through this medium the-spindle 24 my invention in a specific form, the scope of my,

invention is to be measured by the appended claims formin a part hereof.

Having thus described my invention and illus trated its use, what I claim as new and desire to secure by Letters Patent is:

l. A latch construction for doors comprising a casing, a latch bolt reciprocably mounted therein, a handle adapted to be mounted on the outside of the door and having a supporting plate at one said plate, a spindle having one end rotatably carried by-the plate and projecting into the casing,'means operatively connecting said spindle to the latch bolt, and means operatively connectin said latch lever to the spindle whereby pivotal movement of the former effects rotation of the latter, the pivot of said latch lever lying substantially in the same horizontal plane as the axis of and said last-named connecting the spindle, means being disposed between the plate and the latch casing. i

.2. A latch construction for doors comprising a casing, a latch bolt reciprocablymounted therein,

a handle adapted to be mounted on the outside of the door and having a supporting plate at one end thereof, a latch lever pivotally mounted on said plate, a spindle having one endtrotatably carried by the plate andprojecting into the easing, and means operatively connecting said spindle to the latch bolt, said latchlever having a rearwardly projecting portion adjacent the spin-1 dle and the latter having a laterally projecting part engaged with such portionfor operation thereby, and said part being disposed-between the plate and the latch casing. 1 v I v I 3. A latch constructionfor doors "comprisin'g a casing, a latch bolt reciprocably mounted therein, a handle adapted to be mounted on the outside of the door and having a supporting plate at one end thereof, a latch lever pivotallymounted on said plate, a spindle endwisely connected thereto and rotatablycarried by the plate and 'proand in turn to rotate the hub 16 through which the spindle 24 passes in itsengagement with thekeying orifice 23. This, in effect, will cause retraction of the latch bolt 14 in a manner readily understood by reference to my patent previously mentioned. Release of the thumb operable lever 49 puts into-play the projection springs 20 and 2| previously mentionedand upon the link l8 to restore the retractor I! to its normal position.

The relative location of the stud 39 and the hearing 40 which it provides for the cylindrical.

section 38 of the spindle 24 makes for a compact arrangement of the door latchoperating mechanism, all fitting readily within the morticed opening formed in the door, and locates the pivot jecting into the casing, and means operatively connecting said spindle to the latch bolt, said latch lever having a contacting finger portion projecting rearwardly of the pivot closely beside the spindle and the latter having a laterally pro- -J'ecting member directly engaged by said contacting portion of the lever.

4. In combination with a door latch having a bolt, a door handle and mounting therefor including a plate at the upper end of the handle, a

latch lever, means for pivotally mounting said lever on said plate with the pivot disposed to one side of the plate, a spindle operatively connected with the bolt and having one end rotatably carbetween the ears 4! and 48 substantially in the horizontalplane of the spindle 24.

The tongue 53 and the pin 42 which is disposed to project within the slot 4| cooperates with the stops 45 and 46 to limit the pivotal movement of the thumb operable lever 49, assuring against operable-displacement of the parts in relation to each other I By the construction described I have shown a latch operating mechanismv wherein the-retraction of the latch bolt is effected by a thumb oper-.

able lever providing an inexpensive and compact assembly, wherein the thumb operable lever and the mechanism carried thereby is disposed, inclose V adjacency to the latch bolt operating spindle proj'ecting throughthe latch casing. It will be observed that while I have described and illustrated latch lever, means for pivotally mounting. said lever on said plate with the pivot disposed to one.

side of the plate, a spindle operatively connected with the bolt and having one end rotatably carried b the platasaid mounting means comprising projecting flanges on a face of the platewhich supports said spindle, an arm on the lever, and

a laterally projecting extension on the spindle engaged by said arm to elfect rotation of the spindle upon pivotal movement of the lever.

6. In combination with a door latch having a casing and a bolt therein, a door handle and mounting therefor including a plate at the upper end of the handle, a latch lever, means for pivotally mounting said lever on said plate with the pivot disposed to one side of the plate, a spindle operatively connected with the bolt and having one end rotatably carried by the plate, and means, disposed exteriorly of the casing, operatively connecting the latch lever with the spindle, and the pivot of said lever lying in substantially the same plane as the axis of said spindle.

7. A latch construction for doors, comprising a casing, a latch bolt reciprocably mounted therein, a handle adapted to be mounted on the outside of the door and having a supporting plate at one end thereof, a spindle operatively connected with thelatch bolt and projecting from the casing toward said plate, a latch lever pivoted to the platein substantially horizontal alignment with said spindle, an arm on the lever, and means on the projecting end of the spindle with which said arm is engaged to effect rotation of the spindle upon pivotal movement of the lever, said arm extending beyond the end of the spindle and being disposed closely adjacent the side of the spindle.

8. In a spring projected latch bolt having a retractor, the combination therewith of a spindle assembly for actuating the retractor of said latch bolt comprising a plate, an extension providing a bearing on one side of said plate for receiving said spindle for rotatable mounting thereon and having means for connecting the spindle to said ex= tension endwisely, a thumb operable lever having a finger portion arranged to lie substantially in parallelism with said spindle and projecting through said plate, and a lateral extension mounted on said spindle directly in the path of said finger portion whereby direct rotation may be transmitted to said spindle upon actuation of said lever.

9. In a spring projected latch bolt having a retractor, the combination therewith of a. spindle for actuating the retractor having a cylindrical end portion, a plate having a bearing to receive said end portion and means for endwisel connecting the same thereto, a thumb operable lever on the front face of said plate having a finger entering said plate and extending substantially parallel to said spindle, an extension portion on said spindle for direct contacting engagement with said finger to rotate the spindle.

10. In a spring projected latch bolt having a retractor, the combination therewith of a spindle for actuating the retractor having a cylindrical end portion, a plate having a bearing to receive said end portion, a thumb operable lever on the front face of said plate having a finger entering said plate and extending substantiall parallel to said spindle, an extension portion .on said spindle for engagement with said finger to rotate the spindle, and means for limiting the rotational movement of said spindle to assure operative position of said finger and extension portion without displacement from each other.

MORRIS FALK. 

